/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.iotdb.db.queryengine.execution.operator.source.relational.aggregation.approximate;

import java.util.List;

public interface ITopK<T> {

  /**
   * offer a single element to the top.
   *
   * @param element - the element to add to the top
   * @return false if the element was already in the top
   */
  boolean offer(T element);

  /**
   * offer a single element to the top and increment the count for that element by incrementCount.
   *
   * @param element - the element to add to the top
   * @param incrementCount - the increment count for the given count
   * @return false if the element was already in the top
   */
  boolean offer(T element, int incrementCount);

  /**
   * @param k
   * @return top k elements offered (may be an approximation)
   */
  List<T> peek(int k);
}
